Method of producing citric acid.



' citric acid. It is a well known fact that the No Drawing.

UNITED STATES PATENTIOFFICE. I

BOLESLAS zanonsnr, or NEW Yonx, n. Y.

'METHOD OF PRODUCING 'CITRIC ACID.

To all whom it may concern:

Be it known that I, BOLESLAS ZAHORSK], a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented new and useful Improvements in Methods of Producing Citric Acid, of which the following is a specification.

This invention relates to a method'of producing citric acid from saccharose, glucose, levulose and lactose by means of a certain well known fungus which is introduced into solutions of these substances containing certain necessary nutritive salts, and which durlng its growth converts the sugar into spores of certain fungi while developing have the power to convert the sugar into citric acid as above stated to a greater or.

less'degree and applicant is aware that pat ents have been granted for methods of thus obtaining citric acid. In endeavoring to attain successful results I have discovered .that the use of a fungus commonly known as Sterigmatooystie migm, when employed in this fermentation produces excellent results.

used is only 5% of the sugar used, and toincrease the yield of citric acid it is necessary to obtain a growth of Sterz'gmatocystis m'gra which canresist a much higher concentration of citric acid, say. up to about 15%. This I found could be done only 'gradually by cultivating each successive generation 1n a solution containing more-- Specification of Letters Patent.

By using a culture of the fungus which has this high acid resisting power, not only can a citric acid solution having a higher concentration be obtained, but also it is possible' to convert a larger percentage of the sugar used into citric acid.

What I claim as new and desire to secure by Letters Patent is y 1. A process of converting sugar into citric acid, said process comprising the cultivation of a culture of fungus Sterigma-tm stz's nigm in a culture medium containing a out 15% of citric acid, and thereafter inoculating a sugar solution with this culture, allowing the growth of the fungus to proceed in said solution to produce citric acid therein. I

2. A process of converting sugar into citric acid, said process comprising the cultivation of a culture of fungus Stem'gmatocystic m'gm in a culture medium containing about. 15% 'of citric acid, and thereafter inoculating a sugar solution 'containing small amounts of mineral salts, with this culture, allowing the growth of the fungus to proceed in said solution to produce citric acid therein.

3. A procem of converting sugar into citric acid, said process comprising the cultivation of a culture of fungus Sterz'gmatocystz's nigra in a culture medium-containing about 15% of citric" acid, and thereafter inoculating a sugar solution with'this culture, allowing the growth of the fungus to proceed in said'solution while the temperature of solution is maintained between the Patented July 1, 1913. Application filed January 26. 1910. Serial No. 540,267.

limits of 10 and 35 C., to produce citric BOLE SLAS ZAHORSKI. Witnesses:

JAMES F. DUHAMEL, K. ALLEN. 

